This disclosure relates to polycarbonate formed from 2,2-bis (4-hydroxyphenyl)propane (bisphenol A, BPA) with reduced sulfur content, and containing conversion material chemistry, and articles made therefrom.
BPA is widely employed in the manufacture of polymeric materials, such as engineering thermoplastics. For example, BPA is a principle monomer used in the manufacture of polycarbonate. In order to be effective in producing high quality polycarbonate products, higher purity levels are needed of the raw material BPA. The word high in the context of BPA and polycarbonate refers to BPA and/or polycarbonate with lower sulfur levels as a result of the processes encompassed by this disclosure.
Bisphenols, such as BPA, are generally prepared by the electrophilic addition of aldehydes, or ketones such as acetone, to aromatic hydroxyl compounds such as phenol, in the presence of an acidic catalyst. These types of reactions are also referred to as acid catalyzed condensation reactions.
There is a long felt yet unsatisfied need for new and improved processes for producing bisphenol A, which processes could, for example, employ a sulfur containing promoter in the reaction due to its ability to increase reaction conversion and improve selectivity in producing BPA.